Fuel costs represent an increasingly significant expense in the operation of a vehicle, such as an automobile or commercial truck. Route planners, such as route planning navigational systems (e.g. hand-held or vehicular), commonly optimize for distance or time, and in some cases, can provide information relating to fuel availability. Additionally, some vehicle fuel prices are available online. The amount of fuel used by an automobile can be determined by specific characteristics associated with respective parts of the automobile. For example, the amount of gasoline burned by a conventional automobile in general is a function of the physical size of the internal combustion engine as well as the size, weight, and shape of the automobile. However, conventional vehicle route planners do not typically factor in fuel prices or make recommendations to travelers based on such information. Moreover, route planning and vehicle control systems for autonomous vehicles do not provide a robust capability to determine and implement vehicle fuel efficiency.
To further complicate fuel efficiency in route planning and vehicle control, many developments have taken place concerning alternative fuels for vehicles. Conventionally, many automobiles are powered with fossil fuel through an internal combustion engine. However, there are an increasing number of vehicles using power produced from other energy sources, such as an internal battery. Research for alternative fuels for automobiles have focused on hybrid vehicles that use standard gasoline or diesel fuel combined with an alternative power source (e.g., electricity, natural gas, alcohol-based fuels, bio-diesel, etc.). However, there are a variety of alternative energy sources for vehicles today, including gasoline, diesel fuel, biodiesel fuel, compressed natural gas, liquefied petroleum gas, propane, natural gas, hydrogen, ethanol, methanol, stored electricity, and the like. Unfortunately, route planning and vehicle control systems for autonomous vehicles do not provide capabilities to determine and implement vehicle energy efficiency for these alternative vehicle energy sources.